1. Field of the Invention
The present invention relates generally to the field of convertible tops for automobiles and more particularly to the field of convertible top conversions for modern, midengine sports-type cars.
2. Discussion of the Prior Art
Convertible automobiles (convertibles) have always been popular with certain segments of the driving public. And until about the mid 1970's all of the major United States automobile manufacturers produced factory-made convertibles in at least some of their automobile product lines. Because these factory-built convertibles were manufactured on the automotive companies' production lines as variations of hardtop models, the cost to buyers of convertibles was usually not substantially greater than that of comparably equipped, hardtop automobiles of the same model type.
However, as automobile air conditioning became more common and as national safety standards relating to roll-over strength of automobiles became more stringent, the factory production in this country of convertibles was gradually phased out and was completely stopped in about 1978. New convertibles were then available only in some few types of imported automobiles, notably in expensive foreign sports cars, and in relatively costly, customized conversions of small foreign and domestic hardtop automobiles.
The fascination of many motorists with convertibles did not, however, die with the ending of domestic convertible manufacturing. To the contrary, the unavailability of new, factory-built convertibles seemed to enhance or revive public interest in convertibles and older, factory-produced convertibles became sought after, often as collectors' items. Such used convertibles tended to increase, rather than to decrease, in value and the reconditioning, by specialty shops, of certain popular models of convertibles became a profitable business.
As interest was regained in convertibles and as conversion of new hardtop automobiles into convertibles became more common and profitable, the major U.S. automobile manufacturers, in about 1982-1983, reintroduced convertible versions of some of their smaller, sporty models.
However, so far is known by the present inventors, none of the automobile manufacturers (except American Motors Corporation) providing, through their dealers, convertibles to buyers actually construct the convertibles on their own production lines. Instead, for such reasons as economy of manufacturing, considering the still comparatively small numbers of convertibles sold, most automobile manufacturers presently ship out, to special conversion facilities, completely manufactured hardtop automobiles. In these conversion facilities, the hardtop automobiles are converted by cutting the tops off, installing convertible top mechanisms and reinforcing the automobile frames to compensate for removal of the hardtops (which add to body rigidity).
Such convertible conversions, because requiring substantial structural modifications of the automobile being converted, have usually been time consuming and relatively costly, typically adding on the order of about $4,000, and in some instances, up to about $35,000 to the buyers' cost of the hardtop automobile used in the conversion.
Part of this high additional cost for convertibles, as compared to comparable hardtop automobiles, is attributable, under present conversion practices, to cutting off and discarding a significant part of the completely built automobile. Thus, the buyer not only pays the cost of a completely manufactured hardtop automobile, but also pays additionally for removing and throwing away part of the automobile. In contrast, so far as is known, previous factory-assembled convertibles were never first completely assembled as hardtops.
Another factor contributing to the present high cost differential between convertibles and comparable hardtops is that the automobiles being converted were neither designed nor constructed with convertible conversion specifically in mind. Thus, considerable difficulties are often encountered in effecting a satisfactory and attractive conversion. For example, a hardtop automobile may not provide sufficient space for a convertible top mechanism of economical design; specially complicated convertible top mechanisms, which are costly to manufacture, must, therefore, often be constructed. Additionally or alternatively, interior parts of the automobile being converted ordinarily must be cut away to provide space for accommodating or accessing the convertible top mechanism, thereby often requiring considerable reupholstery work. Moreover, because of access it is generally more costly to reinforce the existing frame of a converted automobile than it would be to reinforce the frame, or provide a more rigid frame, during automobile assembly.
Particular original design problems are associated with the conversion of several, currently popular midengine, hardtop automobiles to convertibles. These midengine automobiles, which include General Motors' Pontiac Fiero, Toyota's MR-2 and the out-of-production Porche 914, do not, in fact, have the engine in the middle but rather position the engine forwardly of the rear axle and behind the driver's and passenger's compartment, such compartment being more or less at the longitudinal middle of the automobile.
In order to enable working access to the engine compartment of a so-called midengine automobile, rear deck lids (in effect engine hoods) covering the engine compartment opening typically extend forwardly, usually much further forward than the trunk lids of conventional, front engine automobiles or than the engine compartment deck lids of rear engine automobiles which have their engines more rearwardly positioned than those of midengine automobiles.
Thus, midengine rear deck lids, which are typically hinged at their forward ends, extend to closely behind the driver's seat. Accordingly, midengine automobiles are two seaters, although a small jump seat may be provided behind the driver's and passenger's seats. The rear windows of midengine automobiles are, as a consequence, located far forwardly, adjacent the forward edge of the rear deck lid, and are usually vertical, or nearly so, to conserve space.
It can be appreciated that with a long, forwardly extending rear deck, a short driver's and passenger's compartment and a vertical rear window separating the two, the body lines of midengine automobiles would not be expected to be very attractive or appealing to automobile buyers. As a result, the manufacturers, in effect, camouflage midengine automobiles by providing elongate, slender roof rear quarter panels or webs which extend rearwardly from the driver's and passenger's compartment along side edges of the rear deck lid. These roof rear quarter panels are generally triangular in shape and cause the roof line, as seen from the side, to closely resemble the roof lines of conventional, front engine two door hardtop automobiles. Additionally, the rear quarter panels may be constructed having recessed regions which appear to be, but usually are not, small windows. Ordinarily, the roof top projects at least slightly rearwardly over the rear window so that the relatively harsh verticle lines of the window are additionally obscured. As a result of such construction, the midengine automobiles are enabled to have long, forwardly hinged rear deck lids which provide good engine compartment access while at the same time are enabled to have a conventional, attractive roof line and roof appearance.
However, the rear window placement and forwardly extending rear deck lid make convertible conversion of such midengine automobiles difficult. On the one hand, fashioning the conversion convertible tops and related mechanism so the tops follow the line of midengine automobiles' rear window (eliminating the rearwardly extending roof quarter panels), to thereby locate the convertible top completely forwardly of the rear deck lid and thereby permit unimpeded opening thereof would result in unattractive, box-shaped tops. Moreover, because the rear windows of such midengine automobiles are so close to the driver's seat, the associated convertible top wells would necessarily intrude excessively into the seating compartment. On the other hand, fashioning the convertible tops to follow the hardtop roof line defined in part by the above-mentioned rear roof quarter panels, so that the convertible conversion looks similar to the unconverted hardtop, would cause rearward regions of the convertible top to extend a substantial distance rearwardly over the rear deck lid. As a result of extending rearwardly over forward regions of the rear deck lid, difficulties would be expected to be encountered in opening the rear deck lid to access the engine compartment.
It is, therefore, an object of the present invention to provide a convertible top mechanism for midengine automobiles which enables the convertible top to extend rearwardly over the rear deck lid while permitting substantially normal opening operation of the rear deck lid.
Another object of the present invention is to provide a convertible top mechanism for midengine automobiles which enables the convertible top to extend rearwardly over forward regions of the rear deck lid and which enables the rear deck lid to be opened, with the convertible top either up or down, without disengaging the top from the automobile.
Additional objects, advantages and features of the present invention will become apparent to those skilled in the art from the following description taken in conjunction with the accompanying drawings.